Politicians will disappoint you.

EVERY LIBERTARIAN KNOWS the script: "Never fall in love with politicians. They will always disappoint you."

This spring in Washington was rough on several political figures' libertarian fan clubs. Start with the second-time's-the-charm effort by House Republicans to, well, not repeal and replace Obamacare exactly, but to tinker around its edges--mostly in the form of reduced burdens on taxpayers and insurance companies.

"The [American Health Care Act] repeals fewer than 10 percent of the provisions in the Affordable Care Act," one prominent pro-market legislator explained. If passed, it "will continue to drive up the cost of health insurance--while bolstering the largest insurance companies--and the modifications contained in the AHCA cannot save it. Many of the AHCAs provisions are poorly conceived or improperly implemented."

Yet that same critic--Rep. Justin Amash (R-Mich.), a libertarian favorite and key member of the influential House Freedom Caucus--voted for the flawed measure on May 3, even after expressing his "disgust" with the rushed, top-down process that produced it. What gives?

"When deciding whether to support a bill, I ask myself whether the bill improves upon existing law, not whether I would advocate for the policy or program if I were starting with a blank slate," a clearly rattled Amash wrote on his Facebook page. (One of the congressman's many charms is that he explains virtually all of his congressional votes on social media.) "In other words, the proper analysis is not whether it makes the law good but rather whether it makes the law better. In this case, I felt comfortable advancing the bill to the Senate as a marginal improvement to the [Affordable Care Act]."

That wasn't the only clenched-teeth reaction from a Freedom Caucus member voting "yes." "Ultimately," Mark Sanford (R-S.C.) said, "the vote came down to one simple question: Do we kill the bill and stop the debate from advancing to the Senate, or not?"

Such comments suggest that a voting bloc known for its philosophical rigor was also being influenced by some cruder power dynamics. As Caucus leader Mark Meadows (R-N.C.) said just before the 217-213 vote, "When you get a phone call from the president and that's followed up by a phone call from the president, followed up by a phone call from the vice president--it needs to get done." Or, in the typically colorful words of Amash pal and "no" voter Rep. Thomas Massie (R-Ky.), "The AHCA is like a kidney stone--the...